Modeling of lossy multiconductor transmission lines for the design of high-speed IC interconnects

This dissertation develops a new technique for the modeling of lossless and lossy multiconductor transmission lines terminated with linear as well as nonlinear networks. The results of our study can be readily incorporated into general-purpose circuit simulators to facilitate transient and crosstalk analyses of interconnects in high-speed digital integrated circuits.;In this research the transfer functions and pulse response functions, respectively, are used to characterize a multiconductor transmission line in the frequency domain and the time domain. If the pulse response functions of an N-conductor transmission line are known, two types of equivalent circuit models can be formulated following a systematic procedure. The type-A model consists of two time-invariant resistive networks and 2N linear dependent current sources, and the type-B model contains two time-invariant resistive networks and 2N linear dependent voltage sources. These models are the first to represent both lossless and lossy transmission lines, and are also amenable to circuit simulation.;We have derived a set of new analytical formulas for computing the transfer functions of a multiconductor transmission line based on modal analysis in the frequency domain. Applying inverse Fourier transform to the transfer functions yields the pulse response functions of the line. We have expressed the pulse responses of a lossless multiconductor interconnect as closed-form solutions for the first time. The study presented herein is comprehensive; the previously reported closed-form solutions for two-and three-conductor transmission lines, with or without the weak-coupling assumption, can be proved to be special cases of our results.;The novelty of this work resides in the fact that it successfully integrates multiconductor transmission line analysis methods with standard circuit simulation techniques. Our simulated results for the two special cases of lossless lines with arbitrary loads and lossy lines with linear loads correspond closely to previous computations. The validity of this technique is also substantiated by the fact that our computation results agree well with experimental data.